APA (7th ed.) Citation

Hillen, F., & Höfle, B. (2015). Geo-reCAPTCHA: Crowdsourcing large amounts of geographic information from earth observation data. International journal of applied earth observation and geoinformation, 40, . https://doi.org/10.1016/j.jag.2015.03.012

Chicago Style (17th ed.) Citation

Hillen, Florian, and Bernhard Höfle. "Geo-reCAPTCHA: Crowdsourcing Large Amounts of Geographic Information from Earth Observation Data." International Journal of Applied Earth Observation and Geoinformation 40 (2015). https://doi.org/10.1016/j.jag.2015.03.012.

MLA (9th ed.) Citation

Hillen, Florian, and Bernhard Höfle. "Geo-reCAPTCHA: Crowdsourcing Large Amounts of Geographic Information from Earth Observation Data." International Journal of Applied Earth Observation and Geoinformation, vol. 40, 2015, https://doi.org/10.1016/j.jag.2015.03.012.